MBBS, MSc (Musculoskeletal Science), University College London, Gower Street, London, United Kingdom. E-mail:
J Rehabil Med. 2021 May 10;53(5):jrm00188. doi: 10.2340/16501977-2780.
Measurement of joint angles is usually performed using a simple goniometer, which can often be time-consuming and inaccurate, however smartphones can measure angles, this technology could be used to measure joint position. Studies of smartphone applications for this purpose lack consistency and homogeneity. The aim of the current study is to analyse the reliability and accuracy of 3 inertial motion unit-based smartphone applications for goniometric measurement, using 3 different industry standards as external controls.
In the first 2 phases of the study, measurements of angles between 90° and 165° (simulating knee extension) using 3 smartphone applications were analysed against the 3 industry standards. In the third phase, the smartphone's raw data was individually analysed against a digital inclinometer across the x, y and z axes.
Results from the 3 phases of this study indicate a high degree of reliability and validity of the applications compared with the industry standards, with no clinically significant deviations. Thus, this technology could be used in a clinical setting. However, further clinical research, focussing on joint motions with greater than a single degree of freedom, is required before the use of such applications for joint position measurement in clinical practice.
关节角度的测量通常使用简单的量角器进行，但这种方法既费时又不准确。然而，智能手机也可以测量角度，这种技术可以用于测量关节位置。目前，用于此目的的智能手机应用程序研究缺乏一致性和同质性。本研究的目的是使用 3 种不同的行业标准作为外部对照，分析基于 3 个惯性运动单元的智能手机应用程序在关节角度测量方面的可靠性和准确性。
在研究的前 2 个阶段，使用 3 种智能手机应用程序对 90°至 165°（模拟膝关节伸展）之间的角度进行了测量，并与 3 种行业标准进行了比较。在第 3 阶段，智能手机的原始数据分别在 x、y 和 z 轴上与数字测斜仪进行了分析。
本研究 3 个阶段的结果表明，与行业标准相比，这些应用程序具有高度的可靠性和有效性，且不存在临床意义上的显著偏差。因此，这种技术可以在临床环境中使用。然而，在将此类应用程序用于临床实践中的关节位置测量之前，还需要进行更多针对具有多个自由度的关节运动的临床研究。
